To determine the slope of the line that models the linear relationship between hours worked and earnings, we can use the formula for slope, which is:
\[ \text{slope} (m) = \frac{\text{change in earnings}}{\text{change in hours}} \]
From the given information, we have two data points:
- For 1 hour: $10
- For 3 hours: $30
Now, let's calculate the changes:
- Change in earnings: \(30 - 10 = 20\)
- Change in hours: \(3 - 1 = 2\)
Now, substituting these values into the slope formula:
\[ m = \frac{20}{2} = 10 \]
The slope is \(10\), which is positive. This indicates that as the number of hours worked increases, the earnings also increase, confirming a positive relationship.
So, the slope is \(10\) and it is positive.